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400hp/400lb-ft ... can I do better?

Discussion in 'The Garage' started by Topdown, Feb 21, 2003.

  1. Topdown

    Topdown 1/2 ton status

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    <font color="red">4-bolt main SBC (.030 overbore) </font>(Thanks again KennyW)
    <font color="red">Forged crank</font> (stock stroke)
    <font color="red">Forged rods </font>(stock length)
    <font color="red">Forged pistons </font>(are hypereutectic better? worth the $$?)
    <font color="red">Trick-Flow aluminum heads 200cc, 2.02(i)/1.60(e) </font>(would I be better off with some Dart Iron Eagle 2.05(i)/1.60(e)?)
    <font color="red">Comp Cams Xtreme energy 268(i)/280(e) (224(i)/230(e)@.050) .477(i)/.480(e)</font>
    <font color="red">1.6 ratio roller rockers</font>
    <font color="red">Moroso 7-quart oil pan with windage tray</font>

    all of which comes to a rough total of<font color="red"> $2000.00 </font>with block work.

    This is the list of parts that Hotrod mag has put together and dyno'd at 400/400+ (most of the parts anyway)

    So, my questions, as stated above, are:
    Are hypereutectic (however thats spelled) pistons better? what is the advantage?
    Would a bigger flow (215cc) head with a 2.05(i)/1.60(e) gain me anything? I am looking for more torque... because the 400hp is plenty.

    Also... general thoughts on the setup? Going to be running a 650cfm carb w/air-gap intake.

    Thanks
    -Ryan /forums/images/graemlins/k5.gif
    <font color="red"> </font>
     
  2. 4x4Freak

    4x4Freak 1/2 ton status

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    Forged pistons are stronger; however, a tighter cylinder wall clearance can be run with the hyp. pistons. Usually smaller valves will get you better low end torque.

    What kind of wheelin are you going to be doing, what gears, tranny, etc.?
     
  3. zcarczar

    zcarczar 1/2 ton status

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    High intake velocity will also help build a lot of low end torque, but that will hurt the top end power. This is why Vortec Heads produce such great torque numbers.
     
  4. Topdown

    Topdown 1/2 ton status

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    sand/mud, not much rock crawling. running a th350 with 373's (for the moment, 4.10's soon) with 32" tires (also for the moment, 33's soon here too)

    Thanks for the input

    -Ryan /forums/images/graemlins/k5.gif
     
  5. Topdown

    Topdown 1/2 ton status

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    good to know. I am not too concerned with top-end... other than I have always wanted a 400hp sbc. /forums/images/graemlins/thumb.gif

    Thanks!

    -Ryan /forums/images/graemlins/k5.gif
     
  6. fortcollinsram

    fortcollinsram 1/2 ton status

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    Well, I went through the same dilema w/ the forged vs. hypereutectic when getting parts for my 454...If you EVER plan on nitrous or a blower, get forged...the are much stronger...BUT, the forged piston expands and contracts more with heat changes than the cast hypereutectic pistons, there for a piston bore clearance of of at least .025" and up is required...with the hyper pistons, you can run it as tight a .010", depending on the piston..when hyper pistons are used, the engine usually has higher comp throughout all the cylinders and burns less oil and has lower emissions. Hyper pistons also tend to be quieter than forged...The advantage the forged has are simple...they are stronger and the looser fit in the bore allows the engine to rev more quickley...I chose the SpeedPro hypereutectic cast pistons that have the skirt that is coated in an anti-frition coating...Mine were a special order deal because I needed a full-floating pin which CAN be hard to get in a 454 cast piston..I ended up paying around $40 per piston...you know, there are some AWESOME deals on e-bay for the hyper pistons...like less than $150 for a good set of pistons and pins...

    Chris
     
  7. Sparky87k5

    Sparky87k5 1/2 ton status

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    Is your truck a daily driver? If so, your choice on cams might be improved upon. Also, do a little research on roller rockers and see how many are guarenteed (sp) for a 100k miles and how much hp increase they give. What compression are you planning? Use the hyper. pistons, much better choice for street use. Remember, it's all about torque, horsepower means little on the street. Look at what GM did with their 383 high torque engine. Think about a roller cam for the street. High flow heads are nice, on a race engine but you can't really see that much difference on the street, running low RPM's and capped up exhausts. Study the cam specs on successful street engines. Think about using a stroker crank (383) for better torque numbers. Having built many of my engines, the high compression, long duration cams, high flow head engines just never gave the excitement on the street as my 383 or present 427 did. No substitute for torque. Hot rod magazine makes it's money from advertizers and many of the engines it "builds" are great, but not really practicable for the real world.
     
  8. bigmack

    bigmack 1/2 ton status

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    I am assuming you have a 350 block. Like has allready been said, look at using a 400 crank. If you want your power range on the lower end of the scale you wouldn't want to use a head with an intake runner that large, I wouldn't go any larger than 180cc, and 2.02/1.60 valves are big enough, and you could probably get by with some 1.94/1.50's. Also I would keep the compression ratio in the 9 or 10 to 1 range.
     
  9. 4x4Freak

    4x4Freak 1/2 ton status

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    You might need to get a higher stall torque converter with that cam. You may want to consider the 4x4 Xtreme cam. I really like mine.

    Here's what I have, maybe it'll help you out a little.

    355 block (350 bored .030)
    Stock rods and crank
    Keith Black hyp. pistons
    Comp Cams 4x4 Xtreme (second from the biggest)
    Stock '79 rebuilt heads
    Stock stamped rockers
    Edelbrock performer intake
    Edelbrock 600 cfm carb
    Headers with dual exhaust

    According to desktop Dyno, it's running about 350 hp and 400 lbs of torque. I plan to upgrade to Vortec heads, roller tip rockers and TPI FI. Right now the comp. ratio is somewhere around 9.5:1, with the head change it should be about 10.3:1. I'm guessing that with the upgrades I will probably be running about 400 hp and 420 lbs. I also plan to use a 1500 or 1800 stall converter.
     
  10. Poohbair

    Poohbair 1/2 ton status

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    I don't generally like to advertise other forums, but the guys in the Performance forum over at Chevytalk.com KNOW THEIR STUFF when it comes to HP/TQ numbers. If you post what you want to build over there they will run it on a Desktop Dyno for you and post the results. For instance, you could check the difference w/ the different heads or different cams.
    I would recommend going to a stroker crank, heads no bigger than 190CC runners (I would get some AFR's), and a roller cam. As far as I am concerned there is no point in building a motor these days unless you are going to have it balanced too. Costs like 150 to 200 bucks, builds HP and increases engine life.
     
  11. K1Orion

    K1Orion 1/2 ton status

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    I'd go with vortec heads. You cant beat the price and they are supposed to be good at making torque. Trick Flow are a little pricey but if you really want aluminum AFR are pretty good. Hyperutectic pistons aren't bad but like others said if nitrous or super/turbo charger are even a possibility go with forged. Roller rockers are a good idea if they will hold up. Comp Cams pro magnum are an option.
    A stroker is a good way to make more torque. There are many kits available and they would be your best bet. You don't want to have clearance problems like others on this site recently. Another cheap trick is a crank scraper. Yor cam choice looks good but I would call comp cams help line and see what they reccomend. I picked my cam myself and had to have machine work done to my heads to run the proper springs /forums/images/graemlins/thumb.gif
     
  12. bowtiepower00

    bowtiepower00 1/2 ton status

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    If you want torque, that head and cam combo is too big. I'd stay under 180 on the runners, and 2.02/1.6 is plenty on the valves. As far as cams go, 268 would work in a 383, but for a 350 it's going to push the powerband too high. If you want aluminum heads, look at AFR. If Iron will do check out Pro-Topline. They make some Vortec style heads that flow better and have standard intake bolt patterns. They are also around the same price as the vortecs. I'd keep the compression around 9 for iron and 9.5-10 for aluminum. Comp makes some extreme 4x4 cams, you might want to look into those. A roller setup will make more torque, but will cost a bit more. If torque is your thing, I'd go with a 383 or 400. You can find quite a few 3.75" cranks with 350 journals, for the same price as a 3.48" crank.
     

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